1. Field of the Invention
The invention pertains generally to meter centers for electrical power distribution systems and, more particularly, to meter centers including a number of meter socket assemblies structured to provide a number of selected phase combinations among a number of meters. The invention also relates to meter socket assemblies for a meter center. The invention further relates to insulative support members for a meter socket assembly.
2. Background Information
Meter centers including a plurality of watt-hour meters are commonly used to measure electric power consumed by, for example, the various tenants of a multi-unit residential site (e.g., without limitation, an apartment building) or commercial site (e.g., without limitation, an office complex).
It is known to provide the same phase combination (e.g., phasings AB, BC or AC) for meter socket assemblies within multiple meter panel boards or load centers. This provides the same phase combination of meter sockets within meter centers having multiple meters. Each of the meter sockets plugs onto a corresponding meter socket assembly structure that accommodates two tenant buses and only two phase buses.
FIGS. 1 and 2 show a conventional meter center assembly 1, which generally consists of a cabinet 3 having an internal longitudinal wall 5 that divides the cabinet 3 into side-by-side meter and disconnect switch compartments 7,9. A plurality of plug-in, socket type watt-hour meters 11 are mounted within the meter compartment 7, one meter 11 for each tenant circuit which is to be metered. Thus, in the example of FIG. 1, the meter center 1 accommodates four tenant circuits each served by its own meter 11. Each tenant circuit is also provided with a disconnect switch 13 such as, for example, a circuit breaker, which is mounted within the disconnect switch compartment 9.
Electric power is provided to the meter center 1 by feeder buses 17 which are electrically connected to the utility lines (not shown) that supply power. Specifically, as shown in FIG. 2, three phase buses 17A,17B,17C and a neutral bus 17N extend horizontally through the cabinet 3 for electrical connection to the utility lines (not shown). A set of supply buses 27 extends vertically within the meter compartment 7 and electrically connects to the feeder buses 17. More specifically, the supply buses 27 generally comprise a pair of spaced apart bus bars 29R,29L, which are each electrically connected to one of the feeder buses 17A,17B,17C by one of the phase balancers 47A,47B. For example, the left supply bus 29L in the example of FIG. 2 is electrically connected to the phase A feeder bus 17A by phase balancer 47A, and the right supply bus 29R is electrically connected to the phase B feeder bus 17B by phase balancer 47B. Phase balancer 47A generally consists of a cylindrical sleeve 49 (shown in hidden line drawing) and bolt 51. Phase balancer 47B generally consists of a Z-shaped member 53 and bolts 55. Thus, the entire meter center 1 is configured in the same manner, in this case phase AB, although it will be appreciated that it could also be entirely phased AC (for feeder buses 17A and 17C) or BC (for feeder buses 17B and 17C).
It is also known to provide a meter center wherein different meters within the same cabinet are phased differently on two different phase combinations (e.g., on two of phase combinations AB, AC, and BC, such as AC and BC). One of the supply buses is divided in order to include a first section being in electrical communication with a first feeder bus (e.g., phase A) and a second section being in electrical communication with a second feeder bus (e.g., phase B) in order to provide a first number of the meter sockets with a first phase configuration (e.g., phasing AC) and a second number of the meter sockets with a different second phase configuration (e.g., phasing BC). A first phase connector (e.g., phase A) electrically interconnects the first section of the first supply bus with a corresponding feeder bus (e.g., phase A), a second phase connector (e.g., phase B) electrically interconnects the second section of the first supply bus with a corresponding feeder bus (e.g., phase B), and a third phase connector (e.g., phase C) electrically interconnects the second supply bus with a corresponding feeder bus (e.g., phase C).
Among other disadvantages, this makes phase balancing (i.e., distributing the electrical load) impossible among all three phase combinations in the same meter center.
There is, therefore, room for improvement in meter centers and in meter socket assemblies therefor.